Capturing return value from ExecuteCommand

[koolnitz]

Hi,

I have a ExecuteCommand activity with following properties set:

ExecCommand page
Command: ls
Parameters: #prmDirXml# | wc -l | tr -s ' '' ' | cut -f2 -d" "

Triggers page
Name: Link1 Expression Type:ReturnValue - (Conditional) Expression: = 0
Name: Link2 Expression Type:Otherwise Expression: N/A


Basically, I am checking in a directory for existence of file(s). Idea is to pass the flow to Link1 if no file exists, otherwise Link2.

In Director, it's showing:
waitforfile_excecutecommandactivity1..JobControl (@Execute_Command_10): Executed: ls /data/ds/hub_cmsr2/etl/xml/OI | wc -l | tr -s ' '' ' | cut -f2 -d" "
Reply=0
Output from command ====>
9

Though the output is 9, the trigger is passing the flow to Link1. It's not capturing the return value.

I also tried as below:


Triggers page
Name: Link1 Expression Type:Custom - (Conditional) Expression: Execute_Command_10.$CommandOutput = 0
Name: Link2 Expression Type:Otherwise Expression: N/A

waitforfile_excecutecommandactivity1..JobControl (@Execute_Command_10): Executed: ls /data/ds/hub_cmsr2/etl/xml/OI | wc -l | tr -s ' '' ' | cut -f2 -d" "
Reply=0
Output from command ====>
0

In this case, even if the return value is 0, it always passes the flow to Link2. It is returning the status of command execution, whereas I want to capture the output of command.


Any sugestions?

Thanks!

[kduke]

Early versions of DataStage have a bug where the parameter does not substitute correctly in the Execute Command. This does not appear to be your problem.

The return value is the last command executed. When you string together several commands then I would imagine that they all work succesfully so they return as a group 0. You need to execute a shell script so you can isolate the real return code.

[koolnitz]

Thanks Kim.

I think the ExecuteCommand is returning correct output (may be in wrong format). In the first case above, Director is displaying correct no. of files present in the directory, i.e. 9.

When I try to match $CommanOutput value with 9 or '9', it doesn't match. I tried out with Trim(), Num(), Char() and all the available functions on $CommandOutput to match, still failing.

Anyway, I tried out calling a shell script from CommandActivity. In this case, whenever it finds any file in the specified directory, it goes well. On the other hand, when it doesn't find any file, it throws a Warning, as below:

waitforfile_excecutecommandactivity2..JobControl (@Execute_Command_10): Command sh did not finish OK, reply = '1'

The script which I am calling:

Code: Select all

#!/usr/bin/ksh
#time is the session timeout period in seconds.
time=$1
echo " time= $time"
XMLFilePath=$2
echo "XML file Path is $XMLFilePath "
integer i
i=0
while [ $i != $time ]
do
   if [ -f $XMLFilePath/*.xml  ]
   then
#      echo 'File Found'
      return 0
      exit 1
   else
      sleep 1
      i=i+1
#      echo 'File Not Found'
      return 1
   fi
done

exit 0

How to avoid this warning? Any help will be appreciated.
Thanks!

[kduke]

I think the exit code is what DataStage uses for return code. So exit 0 will be a return code of 0 and exit 1 is return code of 1.

[ray.wurlod]

Have you tried trimming @FM as well as white space from the output? DataStage converts line termination characters into field marks.

[koolnitz]

Bingo!!!

It worked, I just appended @FM for equality check.

Code: Select all

Execute_Command_10.$CommandOutput = 0 : @FM

Ray, you are a genious. Thanks much.